Cargo hoist



July 2, 1946.

W. P. LEAR CARGO HOIS'I' Filed May 15, 1944 5 SheetsSheet l I IN V EN TOR. W/LLM/V P. L/f/IK J1 TTOKNEY W. P. LEAR July 2, 1946.

CARGO HOIST Fiied May 15, 1944 S Sheets-Sheet 2 Q NR isa Q Q Q 3 .ATTOHNEY Jul z, 194

W. P. LEAR CARGO HOIST Filed May 15, 1944 5 Sheets-Sheet 5 INVENTOR. Mil/4M P. Lf/IK' WZ K ATTORNEY Jul 2,1946. w. P. LEAR 2,403,099

CARGO HOIST Filed May 15,1944 5 Sheets-Sheet 4 INVENTOR. W/ZL/AM P. Lf/IR ATTORNEY July 2, 1946.

w. P. LEAR 2,403,099

CARGO HOIST Filed May 15, 1944 5 Sheets-Sheet 5 Patented July 2, 1946 canoo HOIST vWilliam P. Lear, North Hollywood, Calif., assignor, by mesne assignments, to Lear, Incorporated, Grand Rapids, Mich, a corporation of Illinois Application May 15, 1944, Serial No. 535,659

14 Claims.

1 This invention relates to a cargo handling unit which may be either power or manual driven, and more particularly to a novel compact lightweight cargo hoisting and traversing unit particularly suitable for use in cargo airplanes.

The development of relatively large cargo carrying airplanes has led to a demand for a compact lightweight cargo hoisting and traversing unit capable of handling relatively large loads. In particular, there is a demand for a cargo handling unit which is sufilciently light in weight that it will not appreciably affect the carrying capacity of the aircraft, and which is normally powerdriven but may be manually operated in the event of an emergency.

It is among the objects of this invention to provide a novel compact lightweight cargo handling unit, particularly suitable for use in cargo air- Fig. 8 is a longitudinal sectional view through a torque limiting arrangement forming part of a manual drive.

Fig. 9 is a plan view, partly in-section, of a cable spooling mechanism embodying the-invention.

Fig. 10 is a longitudinal sectional view of a portion of Fig. 9. I

Fig. 11 is a cross-sectional view of a speed 8 erning mechanism embodied in the' invention.

Fig. 12 is a schematic wiring diagram illustrating control circuits forming part of the invention.

planes; to provide such a unit including hoisting and traversing drums and selectively operable mechanism for interconnecting-the two drums for actuation as a unit; to provide a cargo hoisting unit including novel means for controlling the rate of lowering a load; to provide a cargo hoisting and traversing unit, particularly suitable for cargo airplanes, and which may be controlled from any point in the cargo carrying compartment of the airplane; to provide a cargo hoisting unit'including novel means for controllably feeding the hoisting cable on t the hoisting drum; and to provide a cargo hoisting and traversing unit including simple and effective automatic remote controls.

These and other objects, advantages and novel features of the invention will be apparent from the following description, taken in connection :vith the'accompanying drawings. In the draw ngs:

General peration Referring to Fig. l, the cargo handling unit of the invention comprises a'compact lightweight traversing and hoisting unit l5 which may be secured to a forward bulkhead I of a cargo compartment ll formed in the fuselage ll of a cargo aircraft. Unit l5 includes a hoisting drum for raising andlowering a load which may be secured to a hoisting device, such as a hook 2|, and a traversing drum for moving a traversing device.

such as a trolley 22, longitudinally of the com- Fig, 1 is a longitudinal sectiona1 view through .the fuselage of a cargo aircraft, illustrating a the Fig. 7 is .abottom plan view of a portion of Fig. 6.

trap door i9. Power operation of unit I5 is controlled by' means of a control box 25 having a series of up," down, "forward" and aft" push buttons, 26, 21, 28 and 29, respectively and a toggle control switch 30. Control box 2! is connected by multi-conductor cable II to a relay box 32 mounted on fuselage .l8. Relay box 32 contains suitable relays operable by push buttons 26, 21, 28 and 29 for controlling the operation of unit l5 to either raise or lower hook 2| or to move the same forward and aft of cargo compartment 11.

In the event of failure of the power supply aboard the aircraft, or when otherwise desired unit I 5 may be conditioned for manual operation by means of a gear shifting lever 33 and a detachable crank handle 34. When so conditioned, the rate of lowering of a load on hook 2| may be controlled by suitable mechanism operated by a, brake handle 35 to which is attached a cable. sufficiently long to reach to any part of cargo compartment ll. Furthermore, cable 3! is likewise sufliciently long that control box 25 may be held in the. hand of an operator standing in any art of the cargo compartment.

Trolley rails 36 are mounted in suitable brackets 31 secured to the roof 38 of the cargo c'ornasoaooo drumandfedontoandoffofthedrum.

by a cable spooling mechanism ll. Mechanism ll maintains tension on cable 43 during the time thatthesameisbeingwound on thehoisting drum. and also properly distributes the cable lengthwise of the drum. Cable ll passes over pulleyllandarormdapulleyllsecuredtohook 4 I1 by which unit I! may be secured to bulkhead II.

The driving means for unit ll comprises a motor secured to bracket II, and driving a pinion I through a torque limiting clutch arrangement :2. The motor is disposed partly within hdusin; BB and partly beyond plate 58. Pinion BI is fl and is fastened at its opposite end It to trolley 2!. The traversing cable 41 is in effect, an endless cable passing one or more times around the traversing drum and around a transfer pulley ls associated therewith. Cable 41 likewise passes around a pulley II, which is secured to the rear bulkhead ll of the cargo compartment by a spring if, and its opposite ends are secured to either end of trolley 22. Spring If maintains tension on cable 41 at all times.

The hoisting and traversing drums are substantially equal in diameter. With the arrangement thus far described, if the traversing drum, and thus trolley 22, are held stationary, rotation of the hoisting drum will raise or lower hook Ii constructioaolhuoeninaandhoisflna c: gigg n Es? unit The internal arrangement and operation of traversingandhoistlngunit ll willnowbe describedindetail with particular referencetol'igs. 2to5. Theunitincludesafraine Ilonwhich aholstingdrumfllndatraversingdrumtl are mounted. Frame II comprises an inner member I! having an outer cylindrical bearing surface rotatably supporting drums is and It.

End plates 1 and II are secured to member 6,

andanoutersheathorcasingilisdisposed except for openings through which .therearoimd,

ctblullmdllngg.

Drum II is formed with an inner cylindrical surface 02 engaging bearing ll on member "5!, andwithrecessportions inwhicharesecured aninternalringgearliandasleeveil. Keysumaintaingearflandsleevei'lagainstrotaticnwithrespecttodrumll. Aspurgearll, havingadiametersubstantisllyequaltothatof drumll.issecuredtosleeve|lbyscrewsli,and drivesspooling ofdrumllissmrallygroovedtoreceiveholsting cable.

Traversingdrumtlhasanoutersurfaceformed withapairofgrooves'llinwhichisdlsposed hoistingeablel'l. Bearings'llandllaredlsposed, reapectivelmbetwemmemberltanddrumlland aslesvelltowhiehdrumliissecured. Onth'e.

innsrsurfaceoffleevellaninternalringgear 'llissecured. Abearingll'lsdisposedbetween the'outeredgeofdrumllandendplate Bland asimilarbearingllisdisposedbetweengearll andendplatell.

hacketsllandll extendacroas memberllandaresecuredtoshoulderflthereonbyscrewslland. Endplatellisformed with a large aperture OI. as shown more clearly ll. The outer surface adapted to mesh with a spur gear 93 which is mounted for swinging movement on a bracket N (see Fig. 4) pivoted about the axis of a spur gear 85 with which spur gear ll continually meshes. A crank 98 connects one end of bracket I to a rod 9! associated with the gear shifting mechanism including lever 33 previously referred to.

' Through the medium of lever 31, crank it and bracket 8|, spur gear 93 may be moved from a position where it normally engages pinion II to a manual operating pomtion wherein it engages a. spur gear 98 which is operated by crank 34 in a manner to be described more fully hereinafter.

Spur gear I is mounted on a shaft 100 on the other end of which are a pinion iii and a speed governor I, which latter will be described more fully hereinafter in connection with Fig. 11. Pinion ltl meshes with a spur gear I02 connected through a shaft I03 to driving mechanism for I hoist drum W. Secured to gear It: i a pinion I meshing with a pinion I" on a shaft Ill which connects driving mechanism for unit ll to a selectively operable mechanism llfl which is adapted to condition unit I! for either hoisting or traversing operations.

Mechanism HI includes a spider ill on which are rotatably mounted a plurality of planetary pinions Ill engaging an internal ring gear ll! having an outer braking surface I". Planetary pinions i i I are also in continual engagement with central pinion Ill on a shaft Hi, to which is secured a brake drum HI substantially equal in diameter to ring gear Ill. Shaft Hi connects selectively operable mechanism illto the driving mechanism for traversing drum 85.

The other cooperating parts of selectively operable mechanism III are shown in perspective inFig. 3. Mechanism illismounted onabracket H1 secured to bracket II and to member It of frame Ill. The mechanism includes a pair of brake bands I II and ill cooperating respectively with the braking surface 8 and brake drum Hi. The bands are arranged for alternate braking engagement, and normally band ll! engages brake drum III to maintain traversing drum I stationary.

Selectively operable means are provided for effecting disengagement of brake band ill from drum lit and engagement of brake band Ill with braking surface I". Suchselectively operable means comprises a solenoid Ill and a manual operating lever Ill. Solenoid Ill is secured to a bracket III forming part of bracket Ill, and its plunger III is connected by a link III to one end of a lever I24 pivoted at If. to bracket III. A doubly forked link I21 connects the other end of link ill to the upper end of a T-shflied operating arm ill for brake bands HO and I.

Brakebands Ill and illareformedwlthproiecting ears Ill and III which are free to move. A plate It! extends horisontally from bracket III andis provided with a pair of apertures through which extend pins III and I secured at their lower ends to cars I" and Ill, respectively. The upper ends of the pins are pivotally connected to each end of a cron arm III, formin 1'18. 5,- and with minim-ting brackets l0 and (5 ins part of operating arm ill. and springs III and I31 surround the pins and normally urge ears I30 and I3I downwardly with respect to bracket I32. Arm I28 is provided with an extension I38 connected by a tension spring I40 to an extension I4I of bracket I. normally biases arm I28 to the position shown in Fig. 3, wherein pin I33 is held downwardly and pin I34 is held-in an upward position, thus releasing brake band II8 from braking surface H3 and clamping brake band I I9 against brake drum II5. Adjusting nuts I42 and I43 (Fig. 2) are provided for adjusting the brake bands with respect to the braking surface I I3 and brake drum I I6.

In the event of failure of the power supply to unit I5, manual operating lever I25 is operable to effect manual operation of device IIO. Referringto Figs. 2 and 3, lever I25 is secured to one end of a shaft I44 rotatably mounted in a bracket I45 formed on end plate 58. On the opposite end of shaft I44 is an arm I46 pivotally connected to one arm of a crank I41 pivoted on bracket II1. A link I48 has a longitudinalslot engaging a pin I50 mounted in the opposite end of crank I41. The pin and slot constitute a lost motion arrangement providing for power actuation of device IIO without affecting the position of lever I25. r

The other end of link I48 is pivotally connected to an intermediate point of a lever I5I.pivoted on bracket H1. The lower end I52 of lever I5I engages the upper end I53 of operating arm I28 for brake bands H8 and H9. A latching block Spring I40 is caused to rotate as a unit with gear I85. Through gears I18 and .I11, drum 60 is rotated in a direction to-draw in cable 43 and hoist the load attached to hook 2|. Operation of these elements during a lowering operation will be described in connection with Figs. 6 and 7.

I54 is pivotally mounted on bracket H1 and has block I54 into a latching position.

The outer end of lever I25 is provided with an eye I6I to which a cable or other suitable operating means may be secured for operation of the manual mechanism from a point remote from unit I5. Normally, mechanism I I0 is in the position shown in Fig. 3. Upon outward movement of arm I25, lever I5I moves arm I28 clockwise to release brake band II9 from brake drum H8, and to clamp brake band II8 against brake surface 3. Arm I5I is releasably latched in such position due to its roller engaging in recess I55 of latch block I54.

The driving arrangement for hoist drum 60 will now be described with'particular reference to Figs. 2 and 4. A pinion I84 on the outer end of shaft I03 meshes with. an internal ring gear I65 having an internally threaded hub I56 engaging a threaded portion I81 of a shaft I63 mounted at its inner end in a bearing I10 forming part of bracket 8! and at its outer end in a bearing in end plate 51. Adjacent hub I86, 8. braking disk IN is keyed to shaft I68. Disposed between ring gear I65 and disk I1I is a disk I12 provided with braking surfaces I13 and I14 respectively cooperable with gear I55 and disk I1I.

Disk I12 forms part. of an overrunning clutch and brake arrangement I15, which-will be described hereinafter with particular reference to Figs. 6. and 7. On the inner end of shaft I68 is a pinion I16 which meshes with a spur gear I11 engaging internal ring gear 86 secured to drum 50. When motor 90 is energized, ring gear I65 tends to move to the left along portion I61, due to its threaded engagement therewith, and disk I12 is clamped between gear I85 and disk I1I. Disk "I is keyed toshaft I68 and thus the shaft A spring I58 is v and a plate I60 secured to bracket I I1, and biases secured to end plate 51.

' around drum 'I'hedriving arrangement for traversing drum 65 includes a pinion I on the outer end of shaft II5 which meslies with a spur gear I8I on shaft I82. On the outer end of shaft I82 is a pinion I83 which meshes with an internal ring gear I84 on a shaft I85on the other end of which is a spur gear I38 whichengages ring gear 18 secured to drum 85.

Normally, selectively operable mechanism H0 is conditioned to cause brake band II9 to engage brake drum 8 maintaining traversing drum 85 stationary. Under such conditions, operation of motor to rotate hoisting drum 80 will cause spider I08 to rotate, and planetary pinions III will simply roll around central pinion H4 and effect free rotation of internal ring gear II2. When solenoid I20 is energized, or when handle I25 is swung counter-clockwise, brake band H8 is clamped against surface I I3 and brake band H3 is released from brake drum II8. When m0- tor 30 is energized or when crank handle 34 is operated, with ring gear II2 held stationary, rotation of spider I08will cause pinions III to rotate around gear II2 and drive pinion II4. This in turn drives shaft II5 connected to the driving .rnechanism for traversing drum 55.

Overrunm'ng clutch and broke The overrunning clutch and brake arrangement I15 is illustrated in further detail in Figs. 6 and '1. Disk I12 is formed with peripheral generally-trapezoidal notches or slots I81 in which ,pin I98 to end plate 51. The other end of brake band I is fastened around a pin I91 on one end of an arm I98 pivotally mounted on a pin 200 The other end of arm I98 is provided with an abutment 20I forming a seat for a spring 202 which, at its opposite end, surrounds an abutment203 on a bracket 204 secured to member 58. Spring 202 normally urges arm I98 in a counter-clockwise direction, as viewed in Fig.6, clamping band I95 tightly I9 movement thereof.

When motor 90 is energized in a direction to cause rotation of drum 80 for a hoisting movement, disk I12 rotates counter-clockwise, as viewed in Fig. 6. and balls I88 move toward the larger end of slots I81, against the force of springs I80, providing for rotation of disk I12 with respect to brake drum I9i. As previously explained, under such conditions, gear I85 moves to the left along threaded portion I61 of shaft I88 to clamp disk I12 between itself and disk I1I which is keyed to shaft I88. During a lowering operation, motor 90 drives gear .I 65 in such a di; rection that it tends to move to the right along threaded portion I61 releasing itself and disk I1I from engagement with the. brake surfaces I13 and effectively restraining 7 and I'll, respectively, of disk I12. Should the load tend to rotate faster than the speed determined by the speed of rotation of motor ll, shaft I will turn, relative to gear III, in such a direction that gear III will tend to move to the left. as viewed in Fig. 2, to clamp disk I12 betweenitselfanddisk I'll. Thiswill tendtocause rotation of disk I12 ina clockwise direction, as viewed in Fig. 6. Balls in will thereupon be urged to the narrower portion of slots Ill clamping disk "2 against movement with respect to brake drum Ill. These eii'ects tend to counterbalance each other during a lowering operation providing for the load to be lowered at a controlled rate.

Manual operation of traversing and hoisting unit When traversing and hoisting unit ll is conditioned for manual operation, means are provided whereby the load may be lowered at a controlled rate through actuation of brake band Ill. Such means comprises lever II which is pivotally mounted at its lower end between apertured ears 2" formed on the outer surface of end plate IT. A spring 2 normally maintains lever ll in the upper position shown in Figs. 1, 2 and B. when the lever is swung to the lower position shown in dotted lines in Fig. 2, it engages a pin 2" slidably mounted through plate I] and having a slotted inner end 2" engaging a pin 2|. on a cam 2. Cam III is pivotally mounted on a pin 212 and a coil'spring 2|! normally urges cam Y m to a position where it is out of enga ment with the lower end of arm Ill. When lever 25 ew s pin 2.1, it rotates cam 2H clockwise, as viewed in Hg. '1, to. engage arm Ill and swing this arm in a clockwise direction compressing spring 2". This releases brake band II! from engagement with brake drum Ill. The load is then free to drop lmder the influence of gravity, being controlled by suitable operation of lever II to eifect engagement and disengagement of brake band III. Buch lowering movement is,

'shapedrecess222inaflangel2l formedonthe upper end of a hook 2.

Book 224 is adapted to have crank 34 detachably secured thereto. Flange 223 is wovided with a plurality of tapered recesses in its upper face, in which are mounted ball bearings 22' which are disposed between flange 228 and a cup-shaped flange 22' formed onthelowerendofshaftfll. Aspring22'lis disposedbetweenflangefllandasimilarflange 228 wraigh is slidably and rotatably mounted on sum movunmt of cup-shaped flange m is 'limitedbyoftheflangewithabearing III formed inhousingfll. Ifthetorque 'tnnnnittodlhroughhookflle'sceedsaprs selectedamoimtbadlsfllmoveoutofthedeeper oitheirtapered recessestourgeiian e 220upwardly.sprlng221. Buchupward movementmovessqlm'edend 22l of shaft It. out oi engagemmt with recess 22!, those!- This arrangement effectively limits the torque which can be applied through the manual driving arrangement to a safe value predetermined in accordance with the design of unit II. In order to condition the unit for such manual operation, operating arm 83 must be moved in a direction to actuate arm 94 to swing gear 83 into meshing engagement with gear 98 secured to shaft 2 of the manual driving arrangement ill.

Cable spoofing mechanism Figs. 5, 9 and 10 illustrate cable spooling mechanism 4| for properly feeding cable ll to hoist drum it. This arrangement comprises a threaded shaft 23! and a driving shaft Ill, both rotatably mounted in bearings in end plates l1 and It. Shaft 2" is provided with a keyway 2". A gear 231, secured to shaft 2", meshes will gear II secured to drum II and with a pinion 23! rotatably mounted on shaft 240. Pinion 28. is coupled to shaft 2" through the medium of a one way ratchet clutch 22! having a hub member 2 keyed to shaft 2" and normally held byga spring 242 in a position wherein shaft 218 is eflectively coupled to shaft 2".

The hoist cable spooling mechanism includes a housing 243' having an arm 2 extending at right angles thereto and provided with an apertured end through which shaft 2" extends. A nut 24! iixed in such apertured end has threaded engagement with shaft 22!, whereby rotation of shaft 23! will move housing 2|! longitudinally of shafts 235 and 240. A vertical extension 2 is formed on housing Ill and is provided with apertures through which extends shaft 240. A bevel gear 2" is mounted in this extension, and is provided with a key 2" slidably engaging keyway 236. Gear 241 meshes with a bevel gear 2 on the lower end of a vertical shaft 2".

Housing 2" is provided with a recess III closed by cover plates 252 and 2". A grooved pulley 2" is mounted in recess 25! and secured for rotation with shaft 250. Cooperating with pulley Ill is a pulley 2" mounted on a pin "I. Pin 2 is eccentrically mounted between upper and lower circular plates 25'! and 28! secured to a shaft 2" on the upper end 01' which is an arm 2". A spring 282 extends between arm 2" and a'bracket 202 and normally urges arm 2" in a direction to move pulley III into clamping engagement with hoist cable as it passes betweenthis pulley and pulley Ill.

The operation of the cable spooling mechanism is as follows. During rotation of hoist drum I inadirectiontodrawincablellshaft Illis likewise rotated through themediurn of gears II and 231. This moves spooler housing 248 longitudinallyofdnnniltoproperlydisposethecable thereon. whe unit II is operating in a hoisting direction, one-way ratchet chtch its is effective to release pinion 228 from driving connection with shaft 2. Cable It is pulled between pulleys!" and 2", being held under tenslonbysprlng 2.2 urgingpulleylll towardspulley 2". when cable 42 is being unwound from drum ll during a lowering operation, shaft 2 likewise moves spooler housing 2 longitudinally ofdrumiltol p rlyfeedthecableoifthe dmm. During such lowering operation, one-way ratchet clutch 2 effectively couples pinion m to drive shaft 2". The gearing ratio is such thatiheperlpheralspeedofpulley Illisgreater than-the speed with which cable 48 is paid oi! thedrum. 'Ilms,cablel3iskeptundertension fecting entofhook 224 andshaft 22.; 18 between drum ll and spooling arrangement ll.

Speed governor Speed governing device I05 is illustrated in Fig. 11. The device comprises a housing 210 secured to a bracket 21I mounted inside frame 55. Shaft I extends through the housing and bracket and is supported on bearings therein, with gear IOI being disposed within the housing. An annular brake support 212 is mounted on pins 213 secured to :bracket 21!, and provided with a, braking surface 214. Rotatably mounted on shaft I00 adjacent; braking surface 214 is a braking disk 215 having teeth 21.6 around its outer periphery. Disk 215 progressively increases in thickness from a point midway its center and its periphery to the periphery, to form a wedge portion as indicated at 211. Teeth 216 mesh with teeth 218 on an internal ring gear 280 secured to rotate with shaft I00 by a. key 28I. Ring gear 280 is provided with an annular flange 282 extending towards disk 215. A plurality of ball bearings 283 are mounted in the recess provided by wedge portion 211 of disk 215 and flange 282 of gear 280.

The speed governing arrangement operates in the following manner. Rotation of shaft I00 rotates ring gear 280 and, through inter-engagement of teeth 216 and 218, disk 215 rotates therewith. When the speed of shaft I00 reaches or exceeds a predetermined value, balls 283 move outward under the influence of centrifugal force and, due to wedge portion 211 of disk 215, urge this disk toward braking surface 214. This effects a braking action on shaft I00 and associated connected parts until such time as the speed drops below the predetermined value. Device I is effective to limit the speed of rotation of the elements connected to the drums in both directions of rotation, irrespective of whether unit I5 is manually or power operated.

Electric control circuit for the system A schematic wiring diagram illustrating a control arrangement for the cargo hoist unit is shown in Fig. 12. As described hereinabove, poweroperation of traversing and'hoisting unit I5 through motor 90 and mechanism H0 is controlled by a control .box 25 small in size that may be carried in the hand of an operator. Motor 90 comprises an armature 285, a shunt field winding 286 and a series field winding 281. Box 25 includes up and down" push buttons 26 and 21, respectively,

. forward and aft push buttons 28 and 29,

respectively, and main control switch 30. C- sure of switch 30 energizes a. main control relay 290 from a source of direct current 29! through a conductor 292. Relay 290 operates its armature 293 to connect one terminal of source 2! to the system, thus conditioning the same for operation. Shunt field winding 286 is thereby continuously energized, for a purpose to be described, over the following circuit: negative terminal of source 28I, conductor 289, shunt field winding 286, conductor 294, junction point 295,

- Depression of push button 28 damage due toaccidental depression of two or more push buttons at the same time. Push button 26 also closes a circuit through "up relay 3I I, which is the same as the circuit previously described as far-as junction point 306. One terminal of relay 3 is connected to junction point 306 and the other terminal is connected to battery through thermal cut-out 30I, conductor 298 and relay armature 293. When energized, "up relay 3 disengages its armature 3I2 from contact point 3I3 and engages it with contact point 3I4.

Motor armature 285 is thereby connected in parallel with shunt field winding 286' over the following circuit: junction point 3| 5 in conductor 289, conductor 3I6, armature 3I1 of down" relay 3I8, conductor 320, motor armature 285, conductor 32l, relay armature 3I2, contact point 3, conductor 323, series field winding 281 and junction point 295; the remainder of the. circuit being the same as that for shunt field winding 288. Motor is thus energized to rotate hoist drum 60 in the direction to wind up hoist cable 43 thereon.

When the load has been raised to the desired level, push button 26 is released. This deenergizes relays 301 and 3, with the armatures 3I0 and all of these relays assuming the positions shown in Fig. 12. Relay armatures 3I2 and 3" thereby complete a short circuit including motor armature 285, while shunt field winding 286 remains continually energized, as described. The result of the short circuiting of motor armature 285 with the continued energization of shunt field winding 286 is to effect dynamic braking of motor 90, bringing the system connected thereto to a substantially instantaneous stop. Motor 90 junction point 326 through relay 3I8, thermal cut-out 30I and conductor 298 and relay armature 293. Relay 3I8 disengages its armature 3I1 from contact point 321 and engages it with contact point 328.

Under such conditions, armature 285 and series field winding 281 are energized for rotation of the motor in a reverse direction over the following circuit: conductor 289, junction point 3I5, relay armature 3I2, conductor 32l, motor armature 285, conductor 320, relay armature 3I1, contact point 328, conductor 330, conductor 323, series field winding 281, conductor 296, conductor 238 and relay armature 293. The motor is thus energized for rotation in a direction to unwind cable 43 from drum 60. When push button 21 is released, a dynamic braking circuit for motor 90 is completed 'in the same manner as previously described.

, When it is desired to traverse trolley 22 in a forward direction,push button 28 is depressed. closes the up energizing circuit previously described, and also closes a parallel circuit through solenoid I20 of selectively operable mechanism II 0 as follows: conductor 33I, solenoid I20, conductor 332, condoctor I and relay armature I. As previously described, energization .of solenoid lllconditions the unit for connection of hoist drum II and traversing drum CI for operation together, thus effecting forward movement of trolley 22.

similarly, depression of "aft push button It completes the "down" circuit previously described, and also the same parallel circuit previously described through solenoid III. This eifects connection of drums l and "for operation as a unit thus effecting rearward or aft movement of trolley 22. Upon release of either the forward or "aft" push buttons, a dynamic braking circuit for motor it is completed in the same manner as previously described.

It will be noted that a heating resistance I05 is connected in conductor Ill. Resistance "5 is juxtaposed with thermal cutout unit "I. Should motor I become overloaded, the heating effect of resistance "5 will cause opening of thermal cutout III which in turn breaks the energizing circuits for relays ill and lit, thus electing stopping of the motor. This is a safety feature to prevent damage to the motor.

The described device is a compact lightweight unit completely self-contained and which may be installed at a convenient point in the cargo compartment of a freight carrying airplane. Due to the provision of the relatively long connection cable ll and the push-button control device 25, operation of system may be readily controlled from any point in the cargo compartment. Similarly, lowering and aft movement of the device may be manually controlled from any point in the cargo compartment through cable ll connected to lever 85. The device may be conditioned for either manual or power operation, by

a simply throwing gear shift lever 53 in one direction or the other. Additionally, speed control means are provided for limiting the rate of operation of the mechanism in either a hoisting or lowering operation, irrespective of whether the unit is manually or power actuated. A further feature is the provision of the torque limitin mechanism in the manual drive whereby a torque mater than a predetermined limit may not be imposed on the mechanism. The lowering speed governing mechanism of the invention forms the subject matter of my copending divisional application Serial No. 825.497, filed October 30, 1945, for "Release control for hoisting apparatus.

While a specific embodiment of the invention has been described in detail for the purpose of illustrating the application of the principlesv thereof, it will be understood that the invention may beotherwise embodied without departing from such principles.

What is claimed is; 1. A traversi'nghoist comprising, in combination, a hoisting drum; a traversing drum; a traversing device; a hoisting device mounted on said traversing device; cables connecting said hoisting and traversing drums to said hoisting and traversing devices, respectively; power driving means;

manual driving means; planetary gearing interconnecting said drums; means selectively operable to connect either of said drivingmeans to said planetary gearing; mechanism operatively associated with said planetary gearing and effec tive to condition the same either'to interconnect 70 to said frame; man al l eans detacha l! saiddrumsortohcldsaidtraversing mm tionary; manualmeans for selectively operating saidmechanismtcconnectsaid drumsforoperstion as aunit; other-means for selectively operatl2 interposed between said power driving means and said selectively operable means; and a torque limiting mechanism incorporated in said manual driving means.

2. A traversing hoist comprising, in combination, a frame; a hoisting drum rotatably mounted ments to connect said drums for; rotation as a unit, or to hold said second element stationary to restrain movement of said traversing drum.

3. A traversing hoist comprising, in combination, a frame; a hoisting drum rotatably mounted on said frame; a traversing drum rotatably mounted on said frame; an electric motor secured to said frame; a first internal ring gear rotatable with said hoisting drum: a second internal ring gear rotatable with said traversingldrum; a pinion an engaging said first ring gear; planetary gearing having a first element and a second element; a

lowering speed controlling-device connecting said first element to said pinion; gear means connecting said second element to said second ring Kw:

means selectively perable to connect said motor to said first element; mechanism selectively oper able either to drivingly interconnect said elements to connect said drums for rotation as a unit, or to hold said second element sthtionary to restrain 4o movement of said traversing drum; solenoid means for selectively operating said mwhanism;

and manual means for selectively operating said mechanism to connect said drums for operation as a unit.

4. A traversing hoist comprising, in combination, a frame; a hoisting drum rotatably mounted on said frame; a traversing drum rotatably mounted on said frame: an electric motor secured second element; a lowering speed controlling device connecting said first element to said pinion; gear means connecting said second element to said second ring gear; gear shifting means selectively operable to connect either said electric motororsaidmanualdrivingmeanstosaid planetary gearinl; and mechanism selectively operable either to drivingly interconnect said elements to connect said drums for rotation as a unit or to hold said second element stationary to restrain movement of said traversing drum.

5. A traversing hoist comprising, in combination, a frame; a hoisting drum rotatably mounted on said frame; a traversing drum rotatably mounted on'saidfrsme; an electric motor secured securedtosaid frame; aflrstinternalring gear rotatable with said hcisting'drum; a second in-- i ternal ring gear rotatable with said traversing drum;a lnionengssinssaid firstrinsgear;

ingsaidmechanism; atcrqusiimitingmechanism Il planetary s aling having a first element and a 13 second element; a lowering speed controlling device connecting said first element to said pinion; gear means connecting said second element to said second ring gear; gear shifting means selectively operable to connect either said electric motor or said manual driving means to said planetary gearing; erable either to drivinglyinterconnect said elements to connect said drums for rotation as a unit or to hold said second element stationary to restrain movement of said traversing drum;

solenoid means for selectively operating said mechanism; and manual means for selectively operating said mechanism to connect said drums for operation as a unit.

6. A traversing hoist comprising, in combination, a frame; a hoisting drum rotatably mounted on said frame; a traversing drum rotatably mounted on said frame; an electric motor secured to said frame; manual driving means detachably secured to said frame; a first internal ring gear rotatable with said hoisting drum; a second internal ring gear rotatable with said traversing drum; a pinion engaging said first ring gear; planetary gearing having a first element and a second element; a lowering speed controlling device connecting said first element to said pinion; gear means connecting said second element to said second rin gear; gear shifting means selectively operable to connect. either said electric motor or said manual driving means to said planetary gearing; mechanism selectively operable either to drivingly interconnect said elements to connect said drums for rotation as a unit or to hold said second element stationary to restrain movement of said traversing drum; solenoid means for selectively operating said mechanism; manual means for selectively operating said mechanism to connect said drums for operation as a unit; a brake normally engaging said speed controlling device to control the rate of lowering said hoisting device; and manual means selectively operable to release said brake.

7. A traversing hoist comprising, in combination, a frame; a hoisting drum rotatably mounted on said frame; a traversing drum rotatably mounted on said frame; an electric motor secured to said frame; manual driving means detachably secured to said frame; a first internal ring gear rotatable with said hoisting drum; a second internal ring gear rotatable with said traversing drum; a pinion engaging said first ring gear; planetary gearing having a first element and a second element; a lowering speed controlling device connecting said first element to said pinion; gear means connecting said second element to said second ring gear; gear shifting means selectively operable to connect either said electric motor or said manual driving means to said planetary gearing; mechanism selectively operable either to drivingly interconnect said elements to connect said drums for rotation as a unit or to hold said second element stationary to restrain movement of said-traversing drum; solenoid means for selectively operating said mechanism; manual means for selectively operating said mechanism to connect said drums for operation as a unit; a brake normally engagme said speed controlling device to control therate of lowering said hoisting device; manual means selectively operable to release said brake; and a centrifugal speed governor connected to said planetary gearing. 8. A hoist comprising, in combination, a frame; a hoisting drum rotatably mounted on said frame;

mechanism selectively opa hoisting device including a pulley; a hoisting cable operatively connecting said drum to said hoisting device; power driving means operatively coupled to said hoisting drum; a spooling mechanism mounted on said frame and guiding said hoisting cable with respect to said hoisting drum; gearing connecting said spooling mechanism to said hoisting drum and effective to traverse said spooling mechanism with respect to said hoisting drum; pulley means mounted on said spooling mechanism and engaging said hoisting cable; and driving mechanism connecting said pulley means to said gearing to rotate said pulley means at a rate sufficient to maintainsaid hoisting cable taut with respect to said hoisting drum during lowering of said hoisting device in an unloaded condition.

9. A hoist comprising, in combination, a frame; a hoisting drum rotatably mounted on said frame; a hoisting device including a pulley; a hoisting cable operatively connecting said drum to said hoisting device; power driving means operatively coupled to said hoisting drum; a spooling mechanism mounted on said frame and guiding said hoisting cable with respect to said hoisting drum; gearing connecting said spooling mechanism to said hoisting drum and effective to traverse said spooling mechanism with respect to said hoisting drum; pulley means mounted on said spooling mechanism and engaging said hoisting cable; driving mechanism connecting said pulley means to said gearing to rotate said pulley means at a rate sufiicient to maintain said hoisting cable taut with respect to said hoisting drum during lowering of said hoisting device in an unloaded condition; a ratchet device operative to disconnect said driving mechanism from said gearing during winding of said hoisting cable on said hoisting drum; and resilient means urging said pulley means into gripping engagement with said hoisting cable.

. 10. A traversing hoist comprising, in combination, a frame; a hoisting drum rotatably mounted on said frame; a traversing drum rotatably mounted on said frame; planetary gearing interconnecting said drums, said planetary gearing including a rotatable spider having a plurality of planetary pinions rotatably mounted thereon, a ring gear and a central pinion meshing with said planetary pinions; reduction gearing connecting said spider to said hoisting drum; power driving means; mechanism selectively operable to connect said power driving means to said reduction gearing; a shaft secured to said sun pinion; re-

duction gearing connecting said shaft to said traversing drum; a brake drum secured to said shaft; a first brake band arranged to grip said internal ring gear; a second brake band arranged to grip said brake drum; brake operating means interconnecting said brake bands for alternate operation; resilient means normally urging said second brake band into gripping relation with said brake drum to restrain movement of said traversing drum during a hoisting operation; and mechanism selectively operable to release said second brake band and urge said first brake band into gripping engagement with said ring gear to drivingly interconnect said drums for operation as a unit during a traversing operation.

11. A traversing hoist comprising, in combination, a frame; a hoisting drum rotatabl mounted on said frame; a traversing drum rotatably *mounted on said frame; planetary gearing interconnecting said drums, said planetary gearing including a rotatable spider having a plu- 'saidbrak 15 rality of planetary pinion; rotatably mounted thereon, a ring gear and a central pinion meshing with said planetary pinions; reduction gearinl connecting said spider to said hoisting drum; power driving means; mechanism selectively operable to connect said power driving means to said reduction gearing; a shaft secured to said sun pinion; reduction gearing connecting said shaitto said traversing drum; a brake drum secured to said shaft; a first brake band arranged to grip said internal ring gear: a second brake band arranged to p said brake drum; brake operating means interconnecting said brake bands for alternate operation; resilient means normally urging said second brake band into 8 1 9 8 relation with said brake drum to restrain movement oi. said traversing drum during a hoisting operation; mean selectively operable to release said second brake band and urge said first brake band into gripping engagement; with said ring gear to drivingly interconnect said drums for operation as a unit during a traversp ration; and a solenoid mechanism and a manual mechanism each selectively operable to operate said selectively operable means to release said second brake band and urge said first brake band into gripp ng engagement with said ring gear to drivingly interconnect said drums for operation as a unit during a traversing operation; said manual mechanism includingtoggle means and an operating lever therefor pivotally connected to said frame.

12. A traversing hoist comprising, in combination, a frame; a hoisting drum rotatably mounted on said frame; atraversing drum rotatably mounted on saidtrame: planetary gearing interconnecting said drums. said planetary gearing including a rotatable spider having a plurality of planetary pinions rotatably mounted thereon. a ring gear and a central pinion meshing with said planetary pinions; reduction gearing connecting said spider to said hoisting drum; power driving means; manual driving means; gear shitting mechanism selectively operable to connect said power driving means or said manual driving means to said reduction-gearing; a shaft secured to said sun pinion; reduction gearing connecting said shaft to said traversing drum: a brake drum secured to said shaft; a first brake band arranged to grip said internal ring 8 a second brake band arranged to grip said brake drum; brake operating means interconnecting e for alternate operation; re-

l8 connect said drums for operation as a unitduring a traversing operation; said manual driving mean including a driving shalt. a hook adap tobe engagedbya detachable crankandatomue limiting spring clutch interposed between said driving shaft and said hook.

13. A. traversing hoist comprising, in combination, a frame; a hoisting drum rotatably molmted on said frame; a traversing drum rotatably mounted on said frame; a traversing device having a pulley thereon; a hoisting device including a pulley; an endless traversing cable passing around said traversing drum and secured to said traversing device; a hoisting cable secured at oneendtosaidhcistinsdrumandattheother end to said traversing device, said' hoisting cable passing around aid pulley; an electric motor secured to said frame; planetary gearing interconnecting said drums; means selectively operable to connect said motor to said planetary gearing; mechanism operatively associated with said planetary gearing and eflective to condition the same either-"to connect said drums for op r tion afllent mean; normally urging said second brake I band into grip in relation with said brake drum to restrain movement oi said traversing drum during a hoisting operation; mechanism selectively operable to release said second brake band and urge said first brak band into grippin g'agement with said ring [tear to drivingly interas a unit for traversing said traversing device or to hold said traversing drlnn stationary during vertical movement 01' said hoisting device: solenoid means for selectively operating said mechanism to connect said drums for operation as a unit; a source or electric current; relay means eflective when energised to connect said.

motor only to said source or current; and remote control means for selectively energizing either said relay means alone, to eil'ect vertical movement of said hoisting device, or said relay means and said solenoid means simultaneously.

to eilect movement of said traversing device while maintaining said hoisting device at a predetermined level with respect to said traversing drum.

14. A traversing hoist comprising. in combination, a hoisting drum; a traversing drum; a

traversing device; a hoisting device mounted on said traversing device; cables connecting said hoisting and traversing drums to said hoisting and traversing devices, respectively; power driving means; manual driving means: planetary gearing interconnecting said drums; means aslectively operable to connect either of said driving means to said planetary gearing; mechanism. 

